1. Field of the Invention
The present invention relates to cleaning devices, more particularly to a cleaning device for use in an image forming apparatus for forming a toner image on a printing medium.
2. Description of Related Art
As an invention related to a conventional cleaning device, a multicolor image recording device described in, for example, Japanese Patent Laid-Open Publication No. 1989-307772 is known. FIG. 16 is a configuration diagram of the multicolor image recording device 500 described in Japanese Patent Laid-Open Publication No. 1989-307772.
The multicolor image recording device 500 includes a photoreceptor 502, a fur brush roller 504, and collection rollers 506 and 508. The fur brush roller 504 gathers toner remaining on the photoreceptor 502. The collection rollers 506 and 508 collect the toner gathered by the fur brush roller 504. The collection roller 508 is provided downstream from the collection roller 506 in a rotational direction of the fur brush roller 504, and has a higher voltage applied thereto compared to the collection roller 506. Thus, the amount of toner to be accumulated in the fur brush roller 504 can be significantly reduced.
However, in the multicolor image recording device 500 described in Japanese Patent Laid-Open Publication No. 1989-307772, toner that is oppositely charged between the fur brush roller 504 and the collection rollers 506 and 508 cannot be collected. More specifically, in the case where toner is positively charged, the fur brush roller 504 is kept at a negative potential level. Moreover, the collection rollers 506 and 508 are kept at lower negative potential levels than the fur brush roller 504. As a result, the toner moves from the fur brush roller 504 to the collection rollers 506 and 508.
However, in the case where the collection rollers 506 and 508 are kept at further lower negative potential levels in order to more efficiently collect toner, toner is negatively charged between the fur brush roller 504 and the collection rollers 506 and 508, resulting in oppositely charged toner. Such oppositely charged toner readheres to the photoreceptor 502 without being collected by the collection rollers 506 and 508. Readhesion of the oppositely charged toner to the photoreceptor 502 might cause some issues such as toner stains and toner image quality deterioration. Moreover, some of the oppositely charged toner might remain in the fur brush roller 504 to be accumulated therein, leading to reduced cleaning performance of the fur brush roller 504.